Primavera Cache Service performs two-way synchronization, that is the service synchronizes data from the local cache to the Cloud Connect database and from the Cloud Connect database to the local cache. The date and time of the last successful synchronization for each project is shown in the Last Sync Date column in P6 Professional.
By default, the synchronization will run at 20 second intervals, which is optimum for most systems. If you need to adjust the frequency at which synchronizations are initiated, change the value for the SyncInterval key in the Primavera.CacheService.Exe.Config file. The value represents the number of seconds between synchronizations. Values lower than 1 are ignored.
To determine which data needs to be synchronized, the last update date or insert date for each data item is compared between the cloud database and the local cache. If your data connection is interrupted, your changes are stored in your local cache database and will be synchronized with the cloud database when connectivity is restored.
During the synchronization process, there is potential for conflicting changes if multiple users are modifying the same data. The synchronization service applies the following rules to resolve conflicts:
- A delete operation will always take precedence over other operations.
- If the same data is modified both on the server and on the client, client-side changes takes precedence over server-side changes.
Note: Primavera Cache Service does not check for the chronological order of updates to resolve conflicts.
For example, consider a situation where Client A and Client B are both connecting to the same cloud database and working in the same project. Client A applies an actual start to activity A1000. The next time Client A synchronizes with the cloud database, the last updated date for activity A1000 will be compared between the local cache database and the cloud database. Since the data is newer on the client than on the server, Primavera Cache Service running on Client A will copy the data for Activity A1000, including the status and actual start date, from the cache database on Client A to the cloud database. The next time Client B synchronizes with the cloud database, the Primavera Cache Service running on Client B compares the last updated date for activity A1000 between the client cache database and the cloud database. Because the cloud database has a later last updated date for activity A1000, the Primavera Cache Service running on Client B will copy the data for activity A1000, including the status and actual start date, from the server to the cache database on Client B.